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The absence of Atg7 in the hematopoietic system leads to lethal anemia. (A) Representative blood smears from anemic 11-week-old mice. (B) Survival curves. (C) Hemoglobin levels. (D) Red blood cell counts. (E) Spleen weight in mg (*P = 0.0159). (F) Upper: H&E-stained paraffin-embedded spleen sections. Lower: representative spleen size, 10-week-old mice.
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Timely elimination of damaged mitochondria is essential to protect cells from the potential harm of disordered mitochondrial metabolism and release of proapoptotic proteins. In mammalian red blood cells, the expulsion of the nucleus followed by the removal of other organelles, such as mitochondria, are necessary differentiation steps. Mitochondrial...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
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... iCre recombinase efficiently excised the loxP-flanked region at the genomic level at both alleles, resulting in any Atg7 Flox allele be- coming Atg7 Null (Fig. S1A). The Atg7 protein was absent in Vav- Atg7 −/− hematopoietic cells (splenocytes and bone marrow-derived dendritic cells) yet still present in the nonhematopoietic kidney cells (Fig. S1B). The absence of autophagy has previously been demon- strated in Atg7 Null/Null cells (18,21). Here we found by electron mi- croscopy (EM) that, whereas wild-type (WT) bone marrow (BM) cells show some autophagic vacuoles, in Atg7 −/− BM these were rare, mostly immature, and open (Fig. S1C). In addition, using endogenous staining of LC3, we determined the constitutive levels of autophagy by immunofluorescence. Whereas all WT BM cells had some punctate staining, very few Atg7 −/− cells had any puncta at all (Fig. S1D). developed a progressively worsening anemia ( Fig. 1 A, C, and D). All Vav-Atg7 −/− mice died between the age of 8 and 14 weeks (Fig. 1B). Approximately 1 week before death, mice be- came symptomatic: weight loss, withdrawal from the group, and lethargy became apparent. Nine-week-old asymptomatic Vav- Atg7 −/− mice displayed significant splenomegaly (Fig. 1E) that disappeared as the anemia progressed. The structural organ- ization of the Vav-Atg7 −/− spleen into white (purple) and red (pink) pulps had disappeared (Fig. 1F). The splenomegaly is a typical sign of stress erythropoiesis observed during ...
Citations
... The same research group further supported this conclusion in a study based on mice lacking the Atg7 gene. They found that these Atg7 −/− mice develop severe anemia, suggesting that accumulate of damaged mitochondria with altered membrane potential was responsible for the high frequency of erythrocyte cell death found in these mice [92]. The conclusion was that a loss of autophagy in erythroid cells leads to the defective removal of mitochondria and severe anemia when in vivo [92]. ...
... They found that these Atg7 −/− mice develop severe anemia, suggesting that accumulate of damaged mitochondria with altered membrane potential was responsible for the high frequency of erythrocyte cell death found in these mice [92]. The conclusion was that a loss of autophagy in erythroid cells leads to the defective removal of mitochondria and severe anemia when in vivo [92]. In this context, as already pointed out in Figure 1, improving ineffective erythropoiesis (IE) is mandatory in β-thalassemia, considering the clinical manifestation associated with IE in β-thalassemia, such as splenomegaly, as well as skeletal deformities due to extramedullary hematopoiesis, osteopenia, pulmonary hypertension, thrombosis, renal diseases, vascular diseases, endocrinopathies, liver diseases and cardiac diseases [93]. ...
The β-thalassemias are inherited genetic disorders affecting the hematopoietic system. In β-thalassemias, more than 350 mutations of the adult β-globin gene cause the low or absent production of adult hemoglobin (HbA). A clinical parameter affecting the physiology of erythroid cells is the excess of free α-globin. Possible experimental strategies for a reduction in excess free α-globin chains in β-thalassemia are CRISPR-Cas9-based genome editing of the β-globin gene, forcing “de novo” HbA production and fetal hemoglobin (HbF) induction. In addition, a reduction in excess free α-globin chains in β-thalassemia can be achieved by induction of the autophagic process. This process is regulated by the Unc-51-like kinase 1 (Ulk1) gene. The interplay with the PI3K/Akt/TOR pathway, with the activity of the α-globin stabilizing protein (AHSP) and the involvement of microRNAs in autophagy and Ulk1 gene expression, is presented and discussed in the context of identifying novel biomarkers and potential therapeutic targets for β-thalassemia.
... The mRNA expression of those six DEGs was assayed through erythroid differentiation of K562 cells (1 day induced by hemin) and HSCs (6 days induced by cytokine cocktail) with or without saracatinib (C), # compared with differentiation without saracatinib and p < 0.05. D Heatmap of K562 and HSCs DEGs associated with tyrosine-protein kinase (n = 73) cell morphology change and enucleation [57] were occurred. The role of saracatinib in those processes needs to determine by further study. ...
Human myeloid leukemia cells (such as K562) could be used for the study of erythropoiesis, and mature erythroid markers and globins could be induced during leukemia cell differentiation; however, the pathways involved are different compared with those of hematopoietic stem cells (HSCs).
We identified the differentially expressed genes (DEGs) of K562 cells and HSCs associated with stem cells and erythroid differentiation. Furthermore, we showed that hemin-induced differentiation of K562 cells could be induced by serum starvation or treatment with the tyrosine kinase inhibitor saracatinib. However, erythroid differentiation of HSCs was inhibited by the deprivation of the important serum component erythropoietin (EPO) or treatment with saracatinib. Finally, we found that the mRNA expression of K562 cells and HSCs was different during saracatinib-treated erythroid differentiation, and the DEGs of K562 cells and HSCs associated with tyrosine-protein kinase were identified.
These findings elucidated the cellular phenomenon of saracatinib induction during erythroid differentiation of K562 cells and HSCs, and the potential mechanism is the different mRNA expression profile of tyrosine-protein kinase in K562 cells and HSCs.
... In contrast to non-specific clearance, mitochondrial autophagy selectively removes damaged or dysfunctional mitochondria through lysosomal degradation, ensuring mitochondrial quality. Research has demonstrated that mitochondrial autophagy is involved in various physiological and pathological processes, including early embryonic development, cell differentiation, and cell apoptosis [77]. In the kidney, which ranks second only to the heart in terms of mitochondrial abundance, mitochondrial damage is a key mechanism underlying kidney disease. ...
Cellular senescence represents an irreversible state of cell-cycle arrest during which cells secrete senescence-associated secretory phenotypes, including inflammatory factors and chemokines. Additionally, these cells exhibit an apoptotic resistance phenotype. Cellular senescence serves a pivotal role not only in embryonic development, tissue regeneration, and tumor suppression but also in the pathogenesis of age-related degenerative diseases, malignancies, metabolic diseases, and kidney diseases. The senescence of renal tubular epithelial cells (RTEC) constitutes a critical cellular event in the progression of acute kidney injury (AKI). RTEC senescence inhibits renal regeneration and repair processes and, concurrently, promotes the transition of AKI to chronic kidney disease via the senescence-associated secretory phenotype. The mechanisms underlying cellular senescence are multifaceted and include telomere shortening or damage, DNA damage, mitochondrial autophagy deficiency, cellular metabolic disorders, endoplasmic reticulum stress, and epigenetic regulation. Strategies aimed at inhibiting RTEC senescence, targeting the clearance of senescent RTEC, or promoting the apoptosis of senescent RTEC hold promise for enhancing the renal prognosis of AKI. This review primarily focuses on the characteristics and mechanisms of RTEC senescence, and the impact of intervening RTEC senescence on the prognosis of AKI, aiming to provide a foundation for understanding the pathogenesis and providing potentially effective approaches for AKI treatment.
... When erythroid differentiation is initiated, OXPHOS is activated to satisfy the energy requirement for differentiation [22]. During TED, mitochondrial function is reduced, autophagy occurs, erythroid cells mature [23], and glycolysis is the main metabolic mode of red blood cells. ROS generated from OXPHOS affect TED, particularly enucleation. ...
Vitamin C is used to treat anaemia; however, the mechanism through which vitamin C promotes erythroid differentiation is not comprehensively understood. The in vitro erythroid differentiation induction system can reveal the differentiation mechanism and provide erythrocytes for clinical transfusion and anaemia treatment. This process can be promoted by adding small-molecule compounds. In this study, we added l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate (AA2P), a derivative of vitamin C, to an erythroid differentiation system induced from umbilical cord blood haematopoietic stem and progenitor cells in vitro and detected its effect on erythroid differentiation using single-cell transcription sequencing technology combined with non-targeted metabolism detection. AA2P increased the proportion of late basophilic erythroblasts, upregulating the expression of erythroid-related regulatory molecules GATA1, KLF1, ALAS2, and the globins HBG and HBB. CA1 is a target gene of AA2P, and CA1 knockdown affected the expression of globin-related genes. AA2P also increased glycolysis and decreased oxidative phosphorylation to facilitate terminal erythroid differentiation and enhanced the proliferation of early erythroid progenitors by altering the cell cycle. These results provide a reliable basis for using vitamin C to improve the efficiency of erythropoiesis in vitro and for the clinical treatment of anaemia.
... After "cleaning" a cell to remove superfluous cytoplasmic content, reticulocytes use the macromolecules produced during the catalysis to sustain the energy demand required for their morphological changes. In this context, several ATG -associated genes, such as ULK1 (ATG1), ATG7, and ATG5, are critical for the clearance of mitochondria and ribosomes [57][58][59]. During reticulocyte maturation in mice, BNIP3L (BNIP3-like protein, also known as NIX), another HIF-1-induced target, is also required for programmed mitochondrial clearance by autophagy [60,61]. ...
Autophagy is a highly conserved cellular degradation process that regulates cellular metabolism and homeostasis under normal and pathophysiological conditions. Autophagy and metabolism are linked in the hematopoietic system, playing a fundamental role in the self-renewal, survival, and differentiation of hematopoietic stem and progenitor cells, and in cell death, particularly affecting the cellular fate of the hematopoietic stem cell pool. In leukemia, autophagy sustains leukemic cell growth, contributes to survival of leukemic stem cells and chemotherapy resistance. The high frequency of disease relapse caused by relapse-initiating leukemic cells resistant to therapy occurs in acute myeloid leukemia (AML), and depends on the AML subtypes and treatments used. Targeting autophagy may represent a promising strategy to overcome therapeutic resistance in AML, for which prognosis remains poor. In this review, we illustrate the role of autophagy and the impact of its deregulation on the metabolism of normal and leukemic hematopoietic cells. We report updates on the contribution of autophagy to AML development and relapse, and the latest evidence indicating autophagy-related genes as potential prognostic predictors and drivers of AML. We review the recent advances in autophagy manipulation, combined with various anti-leukemia therapies, for an effective autophagy-targeted therapy for AML.
... [5][6][7] Mitophagy is an important step for the survival of RBCs during erythroid maturation. 8 It has been demonstrated that the abnormal mitochondria retention in sickle RBCs would be the result of a deficient mitophagy pathway throughout erythropoiesis. 5 Jagadeeswaran et al 9 demonstrated that the use of the lysine-specific demethylase 1A (LSD1) inhibitor (RN-1), and the use of a mitophagyinducing agent mammalian target of rapamycin (mTOR) inhibitor (sirolimus) increased RBC lifespan in a sickle cell mouse model. ...
Abnormal retention of mitochondria into mature red blood cells (RBCs) has been recently reported in sickle cell anemia (SCA) but their functionality and their role in the pathophysiology of SCA remain unknown. The presence of mitochondria within RBCs was determined by flow cytometry in 61 SCA patients and 10 healthy donors. Patients were classified according to the percentage of mature RBCs with mitochondria contained in the whole RBC population: low (0-4%), moderate (>4 and 8%). RBC rheological, hematological, RBC senescence and oxidative stress markers were compared between the three groups. RBC senescence and oxidative stress markers were also compared between mature RBC containing mitochondria and those without. The functionality of residual mitochondria in sickle RBCs was measured by high-resolution respirometry assay and showed detectable mitochondrial oxygen consumption in sickle mature RBCs but not in healthy RBCs. Increased levels of mitochondrial reactive oxygen species (ROS) were observed in mature sickle RBCs when incubated with Antimycin A vs without. In addition, mature RBCs retaining mitochondria exhibited greater levels of ROS compared to RBCs without mitochondria, as well as greater Ca2+, lower CD47 and greater phosphatidylserine exposure. Hematocrit and RBC deformability were lower, and the propensity of RBC to sickle under deoxygenation was higher, in the SCA group with a high percentage of mitochondria retention in mature RBCs. This study showed the presence of functional mitochondria in mature sickle RBCs, which could favor RBC sickling and accelerate RBC senescence, leading to increased cellular fragility and hemolysis.
... This is particularly evident in patients with low-risk MDSs, i.e., patients who are less likely to progress to AML, where high levels of erythroid cell autophagy have been documented during the final differentiation stage [24]. Defects in autophagy were also evident in a study in mice, reporting deficiencies in the ATG7 gene in hematopoietic stem cells (HSCs); these defects may eventually lead to an increased proliferation rate for cells belonging to the marrow lineage similar to that observed in high-risk MDSs [25]. ...
(1) Background: Myelodysplastic neoplasms (MDSs) consist of a group of blood malignancies with a complex biological background. In this context, we investigated the role of autophagy and apoptosis in the pathogenesis and progression of MDSs. (2) Methods: To address this issue, we performed a systematic expression analysis on a total of 84 genes in patients with different types of MDSs (low/high risk of malignancy) versus healthy individuals. Furthermore, real-time quantitative PCR (qRT-PCR) was used to validate significantly upregulated or downregulated genes in a separate cohort of MDS patients and healthy controls. (3) Results: MDS patients were characterized by lower expression levels for a large series of genes involved in both processes compared to healthy individuals. Of importance, deregulation was more pronounced in patients with higher-risk MDS. Results from the qRT-PCR experiments displayed a high level of concordance with the PCR array, strengthening the relevance of our findings. (4) Conclusions: Our results indicate a clear effect of autophagy and apoptosis on MDS development, which becomes more pronounced as the disease progresses. The results from the present study are expected to assist in our understanding of the biological background of MDSs as well as in the identification of novel therapeutic targets.
... Autophagy plays a critical role in the hematopoietic system by regulating the self-renewal of HSCs, differentiation, and development of lymphoid and myeloid progenitors and their precursor cells in response to cytokine signaling [256][257][258]. Several studies indicated that the deletion of ATGs such as FIP200, ATG5, and ATG7 decreases the number of HSCs and diminishes the reconstituting capacity of normal HSCs [167,259]. ...
Autophagy is a dynamic process that regulates the selective and nonselective degradation of cytoplasmic components, such as damaged organelles and protein aggregates inside lysosomes to maintain tissue homeostasis. Different types of autophagy including macroautophagy, microautophagy, and chaperon-mediated autophagy (CMA) have been implicated in a variety of pathological conditions, such as cancer, aging, neurodegeneration, and developmental disorders. Furthermore, the molecular mechanism and biological functions of autophagy have been extensively studied in vertebrate hematopoiesis and human blood malignancies. In recent years, the hematopoietic lineage-specific roles of different autophagy-related (ATG) genes have gained more attention. The evolution of gene-editing technology and the easy access nature of hematopoietic stem cells (HSCs), hematopoietic progenitors, and precursor cells have facilitated the autophagy research to better understand how ATG genes function in the hematopoietic system. Taking advantage of the gene-editing platform, this review has summarized the roles of different ATGs at the hematopoietic cell level, their dysregulation, and pathological consequences throughout hematopoiesis.
... Erythroblasts rely on autophagy via lysosomes to eliminate organelles that impede erythrocyte maturation and function. 66 One study found that knockout of factors essential for autophagy causes anemia in mice, 67 and an unbiased chemical screen revealed that induction of autophagy with the small mole-cule SMER28 enhanced erythropoiesis in induced pluripotent stem cells derived from Diamond-Blackfan anemia patients. 68 Previous work has shown that RPS19 R62W persistently localizes to the nucleus 56 but alters cellular morphology even at moderate expression levels. ...
Technology for crosslinking and immunoprecipitation (CLIP) followed by sequencing (CLIP-seq) has identified the transcriptomic targets of hundreds of RNA-binding proteins in cells. To increase the power of existing and future CLIP-seq datasets, we introduce Skipper, an end-to-end workflow that converts unprocessed reads into annotated binding sites using an improved statistical framework. Compared with existing methods, Skipper on average calls 210%-320% more transcriptomic binding sites and sometimes >1,000% more sites, providing deeper insight into post-transcriptional gene regulation. Skipper also calls binding to annotated repetitive elements and identifies bound elements for 99% of enhanced CLIP experiments. We perform nine translation factor enhanced CLIPs and apply Skipper to learn determinants of translation factor occupancy, including transcript region, sequence, and subcellular localization. Furthermore, we observe depletion of genetic variation in occupied sites and nominate transcripts subject to selective constraint because of translation factor occupancy. Skipper offers fast, easy, customizable, and state-of-the-art analysis of CLIP-seq data.
... When the nucleus is expelled from differentiated RBCs, mitochondrial clearance occurs via autophagy. Loss of BNIP3L, ULK1, or ATG7 leads to mitosis disorder in RBCs and ultimately leads to severe developmental and functional deficits, including those related to mitochondrial retention [23,24]. These results suggest that autophagy promotes cell differentiation and requires large-scale remodeling to adapt to specific cellular functions. ...
Autophagy plays an important role in the pluripotency and differentiation of stem cells. Transcriptome data showed that the autophagy genes MAP1LC3A and MAP1LC3B were significantly upregulated in primordial germ cells (PGCs). The Kyoto Encyclopedia of Genes and Genome (KEGG) results showed that the lysosome signaling pathway, which is related to autophagy, was significantly enriched in PGCs. Quantitative RT-PCR, western blotting, and transmission electron microscopy (TEM) results showed that autophagy was expressed in both embryonic stem cells (ESCs) and PGCs but was significantly activated in PGCs. To explore the role of autophagy in the differentiation of chicken ESCs into PGCs, autophagy was activated and inhibited using rapamycin and bafilomycin A1, respectively. Results of qRT-PCR, flow cytometry, and indirect immunofluorescence showed that the efficiency of PGC formation significantly decreased after autophagy inhibition. Our results showed, for the first time, that autophagy plays an indispensable role in the formation of chicken PGCs, which lays the foundation for studying the mechanism of autophagy in chicken PGCs and in bird gene editing and the rescue of endangered birds.
